Computer exercises help restore vision in stroke
Vision loss or partial blindness frequently occurs among people who suffer stroke. Until recently, most experts believed patients could not recover from it. Practicing computer visual exercises may change that.
Stroke affects nearly 800,000 people in the United States each year, according to the Centers for Disease Control and Prevention. Many of these individuals suffer some degree of vision loss that can range from slight to severe. Vision problems following stroke are caused by damage to the primary visual cortex, which is sthe path taken by all visual information from the eyes to the brain. Depending on the location of the stroke, most patients are blind in 25 to 50 percent of their normal field of vision.
A study conducted at the University of Rochester Eye Institute evaluated the effect of rigorous computer exercises done daily on a computer for several months by people who had gone partially blind as a result of a stroke. The study included seven people who had suffered a stroke that damaged the primary visual cortex, which is the path taken by all visual information from the eyes to the rest of the brain.
During the computer exercises, participants stared at a small black square in the middle of a monitor. At the same time, about 100 small dots appeared on the computer screen every few seconds somewhere in the area associated with where the person’s vision was damaged.
Patients were asked to say whether the dots moved left or right, and when they were correct a bell rang. This sound provided feedback to the brain and accelerated learning. After doing the computer exercises for 15 to 30 once or twice daily, the patients’ brains began to process the information.
The researchers then moved the dots further into the blind areas to help improve sight even more. It can take up to two months for the brain to be retrained to see one part of a blind area. Therefore, people who have many blind areas will need to do the computer exercises for many months to regain some vision.
Doctors may finally have a way to help stroke victims regain some of the vision lost because of stroke. More research into the use of computer exercises for this purpose are needed and are underway.
Huxlin KR et al. Perceptual relearning of complex visual motion after V1 damage in humans. J Neurosci 2009 Apr 1; 29(13): 3981-91.